A research team, led by San Diego State University scientists, has reported a novel way to treat heart disease, delivering a therapeutic gene into the liver of test mice and reducing atherosclerosis by 50 percent.

Engineering bone marrow stem cells to carry a synthetic gene, the scientists then injected the cells into mice where they entered the animals' liver.

"All of the mice we tested appeared healthy, and none showed any unwanted side effects," said Roger Davis, who led the study at SDSU's Heart Institute. The study is described in this week's Proceedings of the National Academy of Science.

"It looks very promising that the technique can be further developed for use in humans to treat several . . . diseases."

Gene therapy has the potential to correct specific genes implicated directly in various diseases. But the field has been hindered because early gene therapy tests in humans have generated unwanted side effects.

"Our novel gene therapy is likely to provide a major breakthrough to safely apply gene therapies for human use," said Davis.

The experiments provide a kind of proof of principle that stem cells can be used to deliver synthetic genes designed to treat disease. Davis said he next hopes to modify the experiment to test its ability in mice to treat genetic diseases such as Gaucher, Tay-Sachs and hemophilia, and to provide immune therapy against specific cancers.

Human trials could follow in two to three years, Davis said.

Dr. Theodore Friedmann, a gene therapy researcher at UC San Diego, called the work "a careful and well-done piece of work (which) describes methods that certainly will be taken up by other scientists.

"This is a terrific and important basic physiological and genetic study, since it suggests a new approach to gene therapy for some kinds of liver disease. . . . It also describes a method that might be extended to diseases of other tissues."

Arctic pollution

The Arctic may be devoid of industry and agriculture, but it is slowly turning into a pollutant dump just the same. The phenomenon is known as the grasshopper effect, because the contaminants – including persistent organic compounds like PCBs and DDT – tend to evaporate in the more temperate zones where they are produced, migrate on air currents and condense in the colder polar region.

"What we've been seeing over the past 15 years is that the Arctic is essentially acting as a depository for many industrial chemicals," said Jules M. Blais, a biology professor at the University of Ottawa.

But the distribution of contaminants in the Arctic is not uniform. "Some places have a lot and others, a little," Blais said.

He and colleagues have now provided an explanation: Seabirds, they write in the journal Science, can concentrate the contaminants in a small area.

The researchers studied the effects of a colony of northern fulmars on Devon Island in the Canadian Arctic. About 20,000 of the birds live along 800-foot cliffs, above a series of ponds. The birds eat fish, squid and other food from the ocean, and the bird waste is washed down the cliffs into the ponds.

All the nutrients in the waste makes the nearer ponds teem with life – mosses, insects, even small birds – in what is otherwise a bleak landscape. The seabirds, Blais said, "support an entire ecosystem below where they are nesting." But analyses of pond sediment show that the seabirds are also passing on DDT, mercury and other contaminants. Ponds closer to the nests had more of the toxins.

The birds are relatively high on the food chain, Blais said. "The things they are eating have bioconcentrated the chemicals," he said. "Essentially, the birds are funneling a large mass of marine carnivores like fish and squid into small areas where they are nesting."

The Rome catacombs, Jewish and Christian, were thought to have dated from between the third to fifth centuries. But researchers from the University of Utrecht in the Netherlands have discovered that the Jewish Villa Torlonia catacomb predated its Christian counterpart by 100 years.

"We believe the Jewish catacombs are older than the Christian ones and therefore might have influenced the supposedly typically Christian idea of burial in catacombs," said professor Leonard Rutgers.

The finding, reported in Nature, raises questions about the extent to which Judaism has influenced Christianity.

"The work we did in the Jewish catacombs gives us further confirmation for the theory that the Jewish roots of Christianity are quite tangible and quite important," Rutgers said.

Rutgers and his team used radiocarbon dating to determine the age of wood from the Villa Torlonia.

"This evidence indicates that the Villa Torlonia catacomb came into use in the second century, a century before the building of the earliest Christian catacombs started," the scientists said in the journal.